Will Tesla Hybrid Power Storage Systems Work With Off-Grid Power

With Tesla Electric Co announcing its Powerwall Hybrid Storage System’s entrance into the Australian market earlier in the year, it’s set to become the new way of generating and storing your own energy – especially since the demise of “feed-in tariffs”. Other well-known companies, such as Samsung, Bosch and LG, have also commercialised these hybrid systems.

The hybrid-based storage systems are designed to store excess solar power in times of low usage and release it in times of peak user demand. However, they are not designed to store enough power to sustain a house for extended periods of nil power input from the generators – be that wind or solar. It raises the question of whether these systems are compatible to go completely “off-grid”?

In short, they are capable to go off-grid but with a few considerations. To truly answer this question it makes sense to see what these systems are capable of. Take, for example, the Telsa Powerwall. It has a battery storage of 7kW/hrs and the LG Chem’s Residential Energy Storage Unit has a battery storage of 10 kW/hrs – which is not bad considering the average use for a home of three people is around 15kW/hrs per day. At night, when the sun has set, these hybrid systems rely on battery storage to power your home. However, if you use more than what is in the battery bank, the system is designed to reconnect to the grid power and recharge. If the sun doesn’t shine the next day, you will have to rely on the grid until the solar panels or wind turbines can again generate enough power. The companies making these systems have made an ingenious way around this – buy 2 or 3 or more. Which is an obvious solution but could very quickly get expensive.

The major difference between a hybrid system and a standard off-grid system is that an off-grid system will typically have anywhere between 3–5 days storage, usually between 30 kW/hrs and 50+/kW/hrs. So if the sun does not shine tomorrow, or the next day, or the day after that, you will still have power available. Furthermore, a hybrid system will cost you around $7000 for one unit, which does not include the solar panels, and the costs soon add up. If you only have one unit, then you will be in a very similar situation to owners of ‘hybrid’ motor vehicles, that is, still filling up at the petrol station.